China Launches 8-Hour Thermal Energy Storage Solar Power Plant, Integrating 900MW of Solar PV

[Net Zero News] China has begun operating a 100MW molten salt tower-type solar thermal power plant that stores sunlight as high-temperature thermal energy and generates electricity when needed. The plant features an 8-hour thermal energy storage system and is integrated with a 900MW solar photovoltaic facility. It is being developed as a large-scale hybrid power project designed to compensate for fluctuations in renewable energy generation and to regulate the duration of power supply.

People's Daily Online reported on October 31, "Xinjiang Fukang: Tower-type Solar Thermal Energy Storage Project Successfully Connected to Grid." China Central Television (CCTV) and Xinhua News Agency also reported on the grid connection. The energy industry specialist media outlet Wedoany detailed the plant's equipment configuration, thermal storage technology, construction progress, and expected generation in its October 31 article, "China Xinjiang Luneng Fukang 100 MW Concentrated Solar Power Plant Connected to Grid."

The 100MW molten salt tower-type solar thermal power plant in Fukang, Xinjiang, invested in and constructed by China Green Development Investment Group, was connected to the power grid on October 30 and began generating electricity. This facility is the sixth molten salt tower-type solar thermal power plant to be connected to the grid in the Xinjiang Uygur Autonomous Region.

The plant is located in the industrial park of Fukang City, Changji Hui Autonomous Prefecture. It constitutes a 1,000MW hybrid power project combining 100MW of solar thermal generation equipment and 900MW of solar photovoltaic generation equipment. The solar photovoltaic facility was previously completed, and with the grid connection of this solar thermal plant, the core equipment of the project combining both generation methods has begun operation.

A notable technology in this project is the molten salt thermal energy storage system, which stores solar energy as high-temperature heat. While conventional solar photovoltaic generation directly converts sunlight into electricity using solar cells, concentrated solar power (CSP) uses mirrors to concentrate sunlight to produce heat, which is then used to drive steam turbines. When combined with thermal storage equipment, the thermal energy captured during the day can be stored and utilized for power generation even during periods of reduced solar irradiance.

The Fukang Power Plant is designed as an integrated project combining large-scale solar photovoltaic generation with high-temperature thermal energy storage solar thermal power generation. This design integrates power generation with the ability to regulate the duration of electricity supply. While solar photovoltaic systems generate substantial electricity during daylight hours, the solar thermal plant stores heat and generates power on demand, thereby enhancing the flexibility of the power supply.

The Fukang Solar Thermal Power Plant is equipped with 15,697 heliostats that track the sun's movement in real time. The total aperture area is approximately 580,000 square meters. The heliostats are designed to concentrate sunlight onto a solar receiver installed at the top of a 236-meter-tall solar tower.

A heliostat is a device that automatically adjusts its reflection angle in response to changes in the sun's position. Although each heliostat is installed at a different location, they are controlled by a system to reflect sunlight toward the same solar receiver. By concentrating the solar radiation energy dispersed over a wide area onto a single receiver, the precise tracking and control of the heliostats play a critical role in the plant's concentration performance.

The solar energy concentrated at the receiver is used to heat molten salt circulating inside the system to approximately 565°C. The heated molten salt is stored in a thermal energy storage facility. When power generation is required, the molten salt passes through a heat exchanger to produce steam at approximately 540°C. This steam drives a 100 MW-class turbine generator to produce electricity.

This generation method differs from conventional solar photovoltaic power, which directly converts sunlight into electricity, as it involves the processes of concentration, heat collection, thermal storage, steam production, and turbine generation. A key technical feature is the ability to store thermal energy, which allows for a partial decoupling of the time when sunlight is available and the time when electricity is generated.

The core of the Fukang Power Plant is a molten salt thermal energy storage system that stores sunlight as high-temperature thermal energy and generates electricity when needed. Unlike conventional solar photovoltaic systems that directly convert sunlight into electricity, concentrated solar thermal power uses mirrors to concentrate sunlight to heat molten salt and store that heat. Molten salt, a heat transfer and storage medium created by melting salts into a liquid state, is responsible for absorbing, storing, and transferring high-temperature heat to other substances.

At the Fukang power plant, 15,697 mirrors focus sunlight onto a 236-meter-tall solar tower, heating molten salt to approximately 565°C. The heated molten salt is stored in insulated tanks. When power generation is required, the molten salt is used to heat water via a heat exchanger, producing steam at approximately 540°C. This steam drives a 100MW turbine generator, and the molten salt, after transferring its heat, undergoes a cycle of being reheated.

The power plant is designed with an 8-hour thermal storage capacity. It is engineered to store thermal energy collected during the day, enabling power generation during the evening or at night when solar irradiance decreases. However, 8-hour thermal storage does not mean that the plant operates at full rated output for 8 hours every day. Actual generation hours and output vary depending on the amount of stored heat and operating conditions.

The molten salt thermal storage system also differs from battery energy storage systems (ESS). Batteries store electricity in the form of chemical energy and then supply it back as electricity, whereas molten salt thermal storage systems store heat and generate electricity through steam turbines. Technical challenges include heat loss from high-temperature equipment, preventing molten salt solidification, and maintenance. This technology has high potential for deployment in regions with strong solar irradiance and sufficient land availability.

The Fukang hybrid power project combines 900MW of solar photovoltaic (PV) generation with 100MW of molten salt solar thermal generation. While both methods utilize solar energy, they differ in the process of electricity production and their roles within the power grid. Solar PV directly converts light into electricity via solar cells to produce large-scale power, while solar thermal generation is designed to manage the timing of power generation through concentration and thermal storage.

In particular, the molten salt thermal storage facility in this project does not function as a battery that directly stores electricity generated by the 900MW solar PV plant. What can be confirmed from the provided materials is that the solar thermal plant stores solar energy, concentrated by its own mirrors, as heat, and operates within a hybrid power structure alongside the 900MW solar PV plant. It has not been confirmed whether there is a separate facility that converts electricity generated by the solar PV plant into heat for storage.

The total installed capacity is 1,000 MW, and the project's planned annual power generation is approximately 1.675 billion kWh. Of this, the 100 MW solar thermal power section is designed to generate an average of approximately 120 million kWh annually. Although the solar thermal generation accounts for a relatively small proportion of the entire project, it is designed to perform a function that is difficult to evaluate based on generation volume alone, as it allows for the regulation of power generation timing through the use of thermal storage equipment.

The Fukang Solar Thermal Power Plant utilizes tower-type molten salt thermal storage generation technology from China’s Cosin Technology. In April 2024, Cosin Technology secured a contract for the supply of concentrator and heat collection system equipment, and in June of the same year, it additionally won a contract for the supply of molten salt storage and heat exchange system equipment.

The concentrator and heat collection system is responsible for concentrating sunlight onto the heat exchanger at the top of the heat tower and heating the molten salt, while the molten salt storage and heat exchange system stores the acquired thermal energy and utilizes it for steam production when power generation is required. Only when these two systems are combined can the entire process be realized, ranging from solar energy concentration and high-temperature thermal storage to steam production and turbine generation.

The construction of the power plant was carried out with multiple companies sharing responsibilities for different equipment. In August 2025, the topmost construction of the heat tower’s outer wall structure was completed, and in June 2026, the supply of auxiliary power for the plant itself was completed. Subsequently, after commissioning the generation equipment and auxiliary systems, grid connection was successfully achieved on October 30.

This grid connection is the result of construction and commissioning that took approximately two and a half years following the major equipment supply contracts. However, the successful grid connection signifies that the plant has been connected to the power grid and begun generation; it does not mean that the designed generation capacity and 8-hour thermal storage performance have been fully verified through long-term commercial operation.

The designed average annual generation for the 100 MW solar thermal power section is approximately 120 million kWh. The expected effects presented by the project side include an annual reduction of approximately 40,000 tons of standard coal and a reduction of approximately 140,000 tons of carbon dioxide.

Standard coal is a conversion standard used to compare the energy quantities of different energy sources. Therefore, the figure of an annual reduction of approximately 40,000 tons of standard coal does not mean that the plant actually used 40,000 tons of coal and then stopped using it; rather, it is a figure converted to the standard coal basis representing the energy substitution effect based on the expected generation.

The approximately 140,000-ton reduction in carbon dioxide is not an actual measured reduction achieved after the plant’s operation, but rather a forecast based on the designed expected generation. The actual greenhouse gas reduction effect may vary depending on the plant’s annual generation performance, the emission factor of the displaced electricity, operating conditions, and other factors. The provided materials do not specify the electricity emission factor or the detailed calculation conditions used to estimate this reduction.

The planned annual generation for the entire 1,000 MW combined power project, which includes a 900 MW solar photovoltaic facility, is approximately 1.675 billion kWh. This figure must be distinguished from the 120 million kWh annual generation attributable to the solar thermal power segment, and the total project’s planned generation should not be interpreted as the performance of a single solar thermal power plant. Furthermore, the forecast of approximately 140,000 tons of annual CO2 reduction pertains specifically to the 100 MW solar thermal power segment and cannot be extrapolated to represent the reduction effect of the entire 1 GW combined power project.

The grid connection of the Fukang power plant exemplifies China’s technical approach to enhancing power supply flexibility by combining large-scale solar photovoltaic generation with long-duration thermal energy storage solar thermal power. Because solar and wind power output varies with weather conditions and time of day, the importance of technologies that manage the temporal mismatch between electricity production and consumption increases as the share of renewable energy in the power mix grows.

Molten salt thermal energy storage power generation serves as a technical solution to this challenge by storing solar energy as high-temperature heat and converting it into electricity when needed. By storing heat during the day and generating power in the evening or at night, this technology can supply electricity during periods of reduced solar photovoltaic output and is designed to ensure operational flexibility in response to fluctuations in power demand.

The grid connection of China’s Fukang power plant illustrates that, in the process of expanding renewable energy, energy storage and the ability to regulate generation hours are as important as installed capacity. South Korea also needs to evaluate the applicability of high-temperature thermal energy storage and concentrating solar thermal power, in addition to existing technologies such as battery energy storage systems and pumped storage, based on domestic solar irradiation conditions, site availability, and economic viability, in order to address the variability of solar and wind power. The government and the energy industry should continuously analyze the actual operational performance and grid contribution of overseas thermal storage power projects and develop concrete strategies for securing long-duration energy storage and power supply flexibility suitable for domestic conditions.

[ NZ News / Shortcom ] The commissioning of China's 100MW molten salt solar thermal power plant is significant as a technical endeavor to store solar energy as high-temperature heat, thereby controlling generation hours, and to integrate with large-scale solar photovoltaic systems to enhance the flexibility of renewable energy power supply. South Korea must also verify the economic viability and grid contribution of long-duration energy storage technologies alongside the expansion of renewable energy facilities, and develop concrete strategies to ensure flexibility suitable for domestic conditions.